Landing gear construction



July 5, 1960 E, H, HARTEL ETAL 2,943,827

LANDING GEAR CONSTRUCTION Filed June 20, 1955 ffffffffffffffffffffffffffffffffffff /l l 1 f/f/ INVENToRs snwm H. MARTEL BY wnLuAM e.wl:sTco-r1,.sr.

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A TT URNE Y '1 2,943,327 Y A LANDING GEAR CoNsrRUcrloN 13min H. Hertel, Cleveland, and williamv B. Westcott," Jr., Cleveland Heights, Ohio, assignors to Cleveland" v.PneumaticIndustries, Inc., a corporation of Ohio. Y

.nnen 4Julie zo, 195s, ser'. N0.516,f4s4

lclaiin. (cram-'111) f This invention relates generally tog-landing gears and more particularly to'a new and improved landing gear and brake system.- l

It is an important object of thisinvention to provide an aircraft landing gear suitable for use on aircraft wherein-the landing ugear cannotrbe retracted into Vthe Wing andfhrefore must be retracted .tintor` the fuselage It is another important object ofthisvinvention to provideV an aircraft landing i-gear incorporating a. piStQn adapted tobe fixed to the aircraft surrounded by a cylinder movable relative to the piston on which is mounted the ground engaging wheel. v

It is still another object of this invention to provide a landing gear incorporating a stationary piston surrounded by a cylinder slidable relative thereto wherein a ground engaging wheel is mounted on the cylinder and the brake actuating mechanism is formed integrally therewith.

Further objects and advantages will appear from the following description and drawings, wherein:

Figure 1 is an elevation of an aircraft equipped with` a landing gear according to this invention;

Figure 2 is an enlarged fragmentary view of the oleo portion of the landing gear; and,

Figure 3 is a side elevation partially in longitudinal section showing the details of the oleo mechanism and of the wheel mounting including the integral brake actuating means.

In the modern high speed aircraft, the thickness of the airfoil has been reduced to a point where it is im- .possible to retract the landing gear into the wing. Therefore, it is necessary to provide a landing gear structure that may be -retracted into the fuselage of the aircraft. A landing gear, according to this invention, overcomes the dill'lculties which are inherent in such applications while providing a light weight structure that meets all of the strength and service requirements.

Referring to the drawings, Figure l discloses the preferred form of landing gear according to this invention wherein the landing gear is mounted on an aircraft having a fuselage into which the landing gear retracts. The-oleo portion 11 of the landing gear is carried by laterally extending strut members 12 and 13 which are mounted on the `fuselage |10. The oleo 11 includes a piston member 16 supported at both ends between the struts 12 and 13 so that it is fixed relative to the aircraft when the landing gear is in the extended position shown in the drawings. Those skilled in the art will recognize that a very strong structure is produced when both ends of the piston 16 are supported in this manner. The piston is provided with an upper cylindrical portion 17 having a flrst cross section and a lower cylindrical portion 18 having a smaller cross section than the upper cylindrical portion *17. A bulkhead 19 separates the two portions and provides the structural connection therebetween. An upper chamber 21 is defined by the upper portion 17, the bulkhead 19 and a cap member 22. Positioned around the piston 16 is a cylinder member 23 provided with a rst gland nut 2.4 at its upper end which firlce 2 l is adapted to slide alongthe outer surface of the upper portion 17 and a second `gland nut ,26 at its lower end adapted to slide along the oute'r surface of the lower por.- tion 18. The two gland nuts cooperate to provide lat-1 eral support or bearing for Athe cylinder 23 and also Y operate with the cylinder and piston 16 to denne a lower annular chamber-27 around the piston. The bulkheadv 19 is formed with a plurality of orifices 28 which connect the upper chamber 21 and the annular chamber 27 to provide a restricted flow connection which dissipates energy ywhenfluid ows'from one-chamber to the Yother y,

and serves to provide shock absorbing action. A flange 25 provided with one or more orifices 30 may be formed on the piston to divide the lower chamber and'provide a rebound chamber 35. u u vThe chamber 27 is completely filled withvoil as is the l lower portion of the chamber 21 and the upper portion is created by the pressure of the fluid contained within landing gear.

the. oleo operating over the differential area between' the upper and lower portions 17 and 18 which provides ther uid spring action utilized to'suPPOrt the load of the craft on the ground. This reaction force urges the'cylinder 23 downwardly relative to the piston 16. A torque arm 29 is mounted on the upper end of the cylinder 23 and is in turn connected to a link anchored on the fuselage 10 to prevent rotation of the cylinder 23 relative to the piston 16 when the landing gear is extended. When the cylinder 23 moves upwardly relative to the piston 16 the volume of rebound chamber 35 increases and hydraulic oil flows therein through the orifices 30. If the aircraft bounces on impact with the ground, the operation of the iluid spring tends to urge the cylinder 23 downward relative to the piston *16. Such a move decreases the volume of the rebound chamber 35 and tends to cause flow of hydraulic oil out of the rebound chamber 35 through the orifices 30. The restriction of such ow resists the motion of the cylinder and thereby tends to reduce rebounding of the cylinder.

The cylinder 23 is formed with an enlarged wheel mounting portion 31 on which is mounted a ground engaging Wheel 32. In the preferred wheel mounting, shown in Figure 3, a spacer member 33 and an outer bearing support 34 are bolted to the mounting portion 31 by means of a plurality of bolts 36. The wheel 32 is journaled at its outer side on the bearing support 34 and adjacent to its inner side on the mounting portion 31 by antifriction bearings 37. A nut 40 threaded on the bearing support 34 retains the outboard bearing 37 in place and thereby completes the mounting of the wheel.

The bearing support 34 is provided with a radially extending brake flange 38 which is xed relative to the A plurality of axially movable rotationally fixed brake discs 39 are mounted on the spacer member 33 by a spline connection 41 and interspaced between the brake discs 39 and the brake ilange'38 are rotatable brake discs 42 which are supported on the Wheel 32 by a spline connection 43 so they are axially movable and rotatably fixed relative thereto. When the right hand brake disc 39 is moved axially -to the left along the spacer member 33, the rotatable Ibrake discs 42 are clamped between the non-rotatable brake discs and frictional drag resists rotation of the wheel.

The mounting portion 31 is provided with symmetrically located bores 44 only one of which is. shown in Figure 3 that serve as the cylinders for brake actuating pistons 46. These pistons 46 engage the right hand stationary brake disc 39 and provide the force for applying Pan-.nml` July 5, 19sosubstantial v actuating structure.

, the rbrakesfwh'en lliicl"u'nder; pressure iis introduced into thetbm'esflfl.through allydraulic tting- 47. I Y

By utilizing a structurewherein the brake actuating means is -integrally formed inthe mounting p.o rrtion`31,r

essaryl` to'providela 'large mounting portion t preventl Vexcessive fst'ressf from oeeurrin'g it is Ydesirable ltoY utilfrze- 15 th'neuntingportiorrfor" brake Yactuating cylinders; 'thus Vfrein the model folgieratin1 andthe'essience o fffthe in- L l ventiol. Therefore; excptfinsofarlas theyearefelaledf f inA the' 'zpmnde'ct'V claim, str uural-n details l mayY be Varied 25 Widely Without;Y modifying-'the inodel 'off operationl Y AC--I coljdnglyg' vthe appended izlaimancl not the aforesaiddetaild description is invention@ v v'2,943,8274'` Y l #as a determinatiye off the-seopefof -the si Y An 'lauztdingI gear` .comprising anoleo-i shock strut,rmeans adapted to connect said oleo shock strut to an aircraft, a laterally extending mounting portion formed integrally with `said oleo shock strut, an outer hearingY supportrhaving a cross section substantially less' rotation relative tot-saidv oleqfshoc 'struc rake operf abl Cllntectedshetween,saidmuuntingpo Y VonA aznwlieel operable toresist relativerotatiou 'therebetween,V said mounting portion--being'formedwith aflaterall'y extend- Y ing bore within the;,inne1 irungierence of said inner bearing,- Vand a fluid actuated piston in Ysaid bore con-Y nected to operate said braket Refereses Cynegi-inline:mejpmisfem L' UNITED STATES PATEK-frs!A n 13127;-696 .5 'Breguet i-ssigaza- 'Y 'Blader 21,192,281- Wallace 2,363,485- -lDQwn 2574,1426. Trevaskls 2,70%;604 Dway- 

